Lesson 3: Accessory Structures of the Skin

Question 1

Glands that secrete oils (sebum) that lubricate and protect the skin and hair, located in dermis, not found in hairless skin, some open into hair follicles, but some open directly onto the skin (lips, glans penis, labia minora, tarsal glands of the eye lids)

Answer 1

Sebaceous glands

Question 2

Glands that secrete salt and water as sweat

Answer 2

Sweat glands

Question 3

What are the two different types of sweat glands?

Answer 3

Merocrine (Eccrine) and Apocrine

Question 4

These sweat glands are found all over the skin, high concentrations found in palms and soles, open directly onto the surface of the skin as a sweat pore, activated in response to hyperthermia or emotional stress

Answer 4

Merocrine (Eccrine) sweat gland

Question 5

Large sweat glands that develop during puberty and located mainly in armpits and genital areas, the duct opens into a hair follicle, DO NOT contribute to thermoregulation but can be activated due to emotional stress

Answer 5

Apocrine sweat gland

Question 6

Modified apocrine glands, located deep in the auditory canal of the external ear, can be combine with sebaceous gland or open independently and directly into the external auditory canal

Answer 6

Ceruminous glands

Question 7

Earwax, formed by the combined secretions of the ceruminous and sebaceous glands

Answer 7

Cerumen

Question 8

What is hair?

Answer 8

An accessory structure in the integumentary system, grows from the depths of the dermis but has its origins in the epidermis, consists of dead, keratinized epithelial cells connected by extracellular proteins

Question 9

What are the functions of hair?

Answer 9

Protects from UV damage, advertises sexual maturity, retains heat, and sensory role

Question 10

What is the anatomy of the hair?

Answer 10

Shaft, root, and the bulb

Question 11

What are the layers of the shaft?

Answer 11

The medulla (inner most layer), cortex (layers of elongated cells, forms significant part of the hair structure), and cuticle (the outer most layer of the hair strand) - extend to the root and bulb

Question 12

Region of hair extending beyond the epidermis

Answer 12

Shaft

Question 13

What are the three important structures found only in the bulb of the hair?

Answer 13

Papilla (inner layer that contains blood vessels and connective tissue), matrix (cells that surround the papilla of the hair, divide to give rise to new cells within hair), and melanocytes (contain melanin)

Question 14

What does the hair follicle contain?

Answer 14

The root and bulb

Question 15

What is the hair follicle composed of?

Answer 15

Epithelial root sheath and a dermal root sheath

Question 16

What happens to the hair in response to the cold?

Answer 16

Tiny muscles called arrector pili are innervated and contract all at once, causing the hair to “stand up straight”

Question 17

A clear plate of dead keratinized epidermal cells

Answer 17

Nail

Question 18

Translucent, visible portion of the fingernail that lies dorsally at the distal end of the digit, overlying the nail bed

Answer 18

Nail plate

Question 19

What are the three parts of the nail plate?

Answer 19

Root (proximal end of the nail, lies beneath the skin and extends several mm into the finger

Body (main portion of the nail that overlies the nail bed)

Free edge (distal overhang of the nail plate over the pulp of the digit)

Question 20

A specialized form of epithelium beneath the nail plate. Adds material (in form of keratin) just below the nail, making it thicker and stronger

Answer 20

Nail bed

Question 21

White, half-moon-shaped area at the proximal end of the nail.

Answer 21

Lunula

Question 22

Below the nail plate, layer of keratinocytes that surround the nail root. Major part of active nail growth

Answer 22

Nail matrix

Question 23

Below the nail plate, underneath the free edge of the nail, thickened area of skin made from the stratum corneum. Secures the nail to the fingertip

Answer 23

Nail hyponychium

Question 24

Type of receptor? Responds to touch, found in dermis of hairless skin, in abundance in hands, feet, lips, and external genitalia, egg-shaped and encapsulated

Answer 24

Tactile corpsucles (Meissner’s corpuscle)

Question 25

Type of receptor? Responds to pressure, located throughout body in the dermis, subcutaneous layer, and deeper regions, oval and encapsulated

Answer 25

Pacinian corpuscle (lamellated corpuscles)

Question 26

Type of receptor? Responds to touch (slowly adapting), located in fingertips, hands, lips, and external genitals, flat saucer-shape and free nerve

Answer 26

Merkel disc

Question 27

Type of receptor? Responds to extreme temp; physical, mechanical, or chemical irritation, located in epidermis (skin) and mucous membranes, bare nerve endings

Answer 27

Nociceptor

Question 28

Type of receptor? Responds to stretching, located in dermis in hands and soles of feet, elongated and encapsulated

Answer 28

Ruffini

Question 29

Type of receptor? Responds to the movement of hair, wrapped around a hair follicle, hairy skin, free nerve ending

Answer 29

Root hair plexus